1. Field
Example embodiments relate to multi-chips having an optical interconnection unit and methods of manufacturing the same. Other example embodiments relate to multi-chips having an optical interconnection unit on a side of the multi-chip and methods of manufacturing the same.
2. Description of the Related Art
In a multi-chip structure in which silicon chips are stacked, a connection method (e.g., a wire bonding method or a through silicon via hole connection method) may be used for an electrical connection between the silicon chips.
In the wire bonding method, as the length of the wire increases, a signal delay may occur if an ultra high speed signal is transmitted. Because the wire bonding method requires bonding pads, the bonding pad area increases as the stacking number of the silicon chips increases, making it difficult to manufacture a compact chip.
In the through silicon via hole connection method, an resistive capacitive (RC) delay is less than the wire bonding method and power consumption is minimal. The through silicon via hole connection requires complicated processes (e.g., a via hole forming process, an insulation process, a metal filling process or the like).
In order to have an optical connection, optical interconnection units including a light emitting device and a light receiving device may be installed on chips facing each other. Because the thicknesses of the light emitting device and the light receiving device are approximately between a few tens of μm to 200 μm, an inter layer distance between the facing chips increases, making it difficult to realize a compact multi-chip package.